title: Four powdery mildew species with catenate conidia infect Galium: molecular and morphological evidence.
abstract: The Erysiphaceae are a group of obligately biotrophic fungi that cause powdery mildew disease of angiosperms. Due to their inability to be cultured on artificial media, the taxonomy of the Erysiphaceae has generally been based on the morphological characteristics of fresh and herbarium specimens. Thus, several morphological species with wide host ranges have long been maintained in this family, even though they clearly consist of several biological species. Erysiphe galii has been known as a powdery mildew of Galium spp. Recently, the former E. galii var. galii has been reassessed as Neoerysiphe galii and E. galii var. riedliana as Golovinomyces riedlianus, along with a taxonomic revision of the generic concept of the Erysiphaceae. The present study was conducted to evaluate the validity of the taxonomic revision of the two varieties of E. galii. During the course of this study, we found that the Galium powdery mildews consist of at least four different species, viz. Neoerysiphe galii, Golovinomyces orontii, G. riedlianus, and an unknown species collected in Argentina. The latter species is described as a new species, Golovinomyces calceolariae. The three species belonging to Golovinomyces are morphologically very similar to each other, i.e. the discrimination between them is rather difficult. The morphological differences of the three Golovinomyces species of Galium are discussed.
authors.affiliation: Graduate School of Bioresources, Mie University, 1577 Kurima-Machiya, Tsu 514-8507, Japan. takamatu@bio.mie-u.ac.jp
authors.forename: Susumu
authors.initials: S
authors.lastname: Takamatsu
authors.forename: Vasyl
authors.initials: V
authors.lastname: Heluta
authors.forename: Maria
authors.initials: M
authors.lastname: Havrylenko
authors.forename: Rangsi
authors.initials: R
authors.lastname: Divarangkoon
mesh_terms: D001203:Ascomycota / Q000145:classification* / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D004271:DNA, Fungal / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D032061:Galium / Q000382:microbiology*; D016533:Mycological Typing Techniques; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013172:Spores, Fungal / Q000502:physiology / Q000648:ultrastructure
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D012339:RNA, Ribosomal, 28S